2515. Impact of Human Parainfluenza Virus Type 4 in Hospitalized Children in Korea

BACKGROUND: Human Parainfluenza virus type 4 (hPIV4) was not thought as the important pathogen of respiratory tract infection so that the characteristics of hPIV4 has not thoroughly elucidated. METHODS: From 2013 to 2016, children who were admitted with respiratory tract infection at the department of pediatrics in Chung-Ang University hospital were enrolled in this study. Nasopharyngeal aspirates (NPAs) were obtained from patients with respiratory tract infection and tested for hPIV types by commercial multiplex reverse transcription polymerase chain reaction (mRT-PCR) assay. We retrospectively reviewed subjects’ medical records, focusing on their epidemiological and clinical characteristics. RESULTS: Of all NPAs, 943 were positive to hPIV. Of hPIV-positive NPAs, 220 were positive hPIV4. 107 patients (48.6%) were male and median age at admission was 2.1 ± 1.7 years (range, 0.2–12.7 years). 215 (97.7%) children did not have an underlying disease. Of 5 children who had underlying diseases, one had asthma, the other had ventricular septal defect, and others had epilepsy. 173 children (78.6%) had a fever and fever duration was 4.1 ± 2.4 days. Their peak temperature was checked as 39.0 ± 0.7℃. The most common symptom of hPIV4 infected patients was cough (80.9%) followed by sputum (60.0%) and rhinorrhea (59.1%). Only six patients had barking cough. Of 6 patients, two had hoarseness and only one patient had stridor with chest wall retraction. The most common diagnosis of hPIV4 was pneumonia (44.5%), followed by acute bronchiolitis (25.0%) and acute pharyngitis (22.3%). Only 2.3% patients were expressed as croup. The prevalence among hPIV types were the highest in hPIV3 (33.7%), followed by hPIV1 (32.4%) and hPIV4 (23.3%). As shown the temporal trends of hPIV types, the most common type was hPIV3 in 2013, hPIV1 in 2014, hPIV4 in 2015, and hPIV1 in 2016. Single infection rate of hPIV4 were 40.5% which were lowest among other parainfluenza virus types (61.1% for hPIV1, 57.6% for hPIV2, and 53.5% for hPIV3). CONCLUSION: The prevalence of hPIV4 was common, compared with those of other hPIV types. Although hPIV4 was usually co-infected with other respiratory viruses, hPIV4 was the important pathogen of lower respiratory tract infection in pediatric patients. Thus, we considered that the detection of hPIV4 by mRT-PCR were needed in pediatric patients DISCLOSURES: J. Y. Park, Korean Society of Pediatric Infectious Diseases: Member, Research grant.